Dexter head



avfz fait Q M N'PETERS. FHOTO-LITHOGRPHER, WASHINGTON, Dv C,

@im im Letters Patent No. 79,071,davted`une 23, 1868,

IMPROVED .HOISTING-APPARATUS.

tithe rlgetnflg etant fr in hp ratiec'#v zitmt :mt mating mi tt tigt time,

TO ALL WHOM ITMAY GONCERN: Y v

Be known that I, DEXTER HEAD, of`Med'usa, in the vcountyofAlbany, and lStnteof New York, have invented a' new and improved 'Hoisting-Apparntus; and- 1 do hereby declare that the following is a full, clear, and exact description thereof, which will-enable others skilled inv the artto makeland use the same, reference 4being had to the accompanying drawings., forming a partj-of this specification, in which-j- Figure 1 represents a side elevation, partly in section,` of. my improved hoisting-apparatus.

i Figure 2 is a `detail transverse section of the same taken on the plane of the line a: x, hg. 1.

Similar letters of reference indicate corresponding parts.

This invention relates to a new device for elevating. loads of silitabledescription, and consistsin the appli cation of a system of levers, known under the denomination. of lazy-tongs. By the use of this invention, articles can be elevated to considerable' heights with'the aid"of but nconsiderable motive-power.

in the drawing, representen crane or derricl, ofsuitable construction and of suitablesize. Freni it is suspended a frame, B, to which the upper levers, a ai, of the lazy-tongs C are, bymeans of a pin, b, pivoted.

The lazy-tongs'eonsist of ltwo sets of zigzag levers, pi-voted together in the mddleot their bars, as shown. One of these central pivots,'e, or a continuation ofit, projecting through the slotted upright or upright's of the frame B, does or may serveas handle for the manipulation of.the apparatus.

Y By moving this pin from the lower to the upper end oi' the slot, the whole system willfbc contracted, as in vfig. 1, as all levers will remain parallel to those elevated withthe pin, and as the pin e is brought nearer to the pin 6, the levers are brought thenvearerlto a horizontal position the nearer c is to b.

The opposite motion of the pin e causes. the levers to expand, as shown by red lines in fig. 1, and thus, by ra-isinxf:r the pin or h'andlec, the load suspended from the device willbe elevateduvhile it will be lowered when c is moved down. Y l

The distance through which the load is`moved Yis nsrmztny times greater than the space in `which c moves as there areijointed pairs of levers employed in the systeni C; consequently, the more such levers are connected, the larger will be the motion of the load in comparison .with -that ofl the handle e. l

The handle c may be raised by suitable mechanism, either by mea-nsof arope or cord, e, which is wound around a windlass, f, or by other'suitable apparatus. i i Y What I claim as new, and desire to Vsecure by Letters Patent, is

The lazy-tongs C, arranged to operate in connection with thc dcrrick A,Islotted frame B, the pulleys, cord e, and windlass f, as herein described, for the purpose specified.V i

The above specification of my invention signed by me, this'th day of April, 1868. l

DEXTER HEAD.'

Witnesses:

WM. F. NINAMARA, ALEX. FQ RoBEn'rs. 

